Parvovirus B19 Infection - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x Parvovirus B19 is a single stranded DNA virus, which is transmitted by respiratory droplets or blood. The virus produces a mild, self-limiting infection in adults, but can cause spontaneous miscarriage or intrauterine death if transmitted to the fetus during pregnancy. Approximately 1 in 400 women become infected with parvovirus B19 during their pregnancy, with vertical transmission to the fetus in up to 33% of cases. Spontaneous miscarriage or intrauterine death occurs in approximately 9% of infected pregnancies. In this article, we shall look at the clinical features, investigations and management of parvovirus B19. By Graham Colm at English Wikipedia [CC BY 3.0], via Wikimedia Commons Fig 1Electron micrograph of negatively stained Parvovirus B19 in blood. Each virus particle is about 25 to 30nM in diameter. Clinical Features Parvovirus infection in adults is usually asymptomatic. The most common clinical feature is symmetrical arthralgia – typically of the proximal interphalangeal joints and/or knees. In children, parvovirus infection manifests with: Upper respiratory tract infection Malaise Headaches Low-grade fever. Erythema infectiosum (slapped cheek syndrome) – a maculopapular rash sparing the nose, eyes and mouth. By Gzzz [CC BY-SA 4.0], via Wikimedia Commons Fig 2Slapped cheek syndrome, seen in parvovirus B19 infection. Investigations In cases where a mother has potentially come into contact with parvovirus B19, viral serology can be performed: Parvovirus specific IgM antibodies indicate recent infection Parvovirus specific IgG antibodies indicate past infection and therefore immunity. Management Women with a confirmed infection of parvovirus B19 should be referred to a fetal medicine specialist for further management. Maternal Parvovirus infection is self-limiting, and does not require treatment. Antipyretics and analgesia can be given. Fetal The main risk of fetal parvovirus infection is fetal hydrops – the abnormal accumulation of fluid in two or more fetal compartments. Management is typically: Serial ultrasound scans and Doppler assessment Starting 4 weeks post infection or at 16 weeks. Repeated every 1-2 weeks, until 30 weeks gestation. If there is evidence of fetal hydrops on ultrasound, the patient should be referred to tertiary centre for intrauterine erythrocyte transfusion. Fetal Hydrops Fetal hydrops is the most common manifestation of fetal parvovirus B19 infection. It is diagnosed by ultrasound scan with features including: ascites, subcutaneous oedema, pleural effusion, pericardial effusion, scalp oedema and polyhydramnios. Fetal hydrops occurs because parvovirus B19 has an affinity for the erythroid system and replicates within the erythroid progenitor cells of the liver and bone marrow. This induces severe anaemia which results in: High output cardiac failure Increased extrahepatic and hepatic erythropoiesis – resulting in portal hypertension and hypoproteinaemia with subsequent ascites. Frequent questions What is Parvovirus B19 and how is it transmitted? Parvovirus B19 is a single-stranded DNA virus primarily transmitted through respiratory droplets or blood. It typically causes mild infections in adults but poses significant risks during pregnancy. What are the common symptoms of Parvovirus B19 infection in children? In children, Parvovirus B19 infection often presents with upper respiratory tract symptoms, malaise, headaches, low-grade fever, and a characteristic maculopapular rash known as erythema infectiosum or slapped cheek syndrome. How is Parvovirus B19 infection diagnosed in pregnant women? Diagnosis of Parvovirus B19 infection in pregnant women can be made through viral serology, where the presence of specific IgM antibodies indicates recent infection, while IgG antibodies suggest past infection and immunity. What are the potential complications of Parvovirus B19 infection during pregnancy? During pregnancy, Parvovirus B19 infection can lead to complications such as spontaneous miscarriage or intrauterine death, with fetal hydrops being the most significant risk, characterised by abnormal fluid accumulation in the fetus. What management strategies are recommended for fetal Parvovirus B19 infection? Management of fetal Parvovirus B19 infection includes serial ultrasound scans and Doppler assessments starting four weeks post-infection. If fetal hydrops is detected, referral to a tertiary centre for intrauterine erythrocyte transfusion may be necessary. Rate This Article